I have a 2007 Ford F-150, 5.4L with the 4R75E automatic transmission. Lately it's been giving me a problem and I want to see what some of the other people think. Here's what's happening...

A few months back I had the transmission serviced and they dropped the pan (for some odd reason) because they told me they had to change the filter. As soon as they were done the transmission has acted a little strange. No metal shavings are in the fluid and the fluid is not dirty, however... if you get on a big hill and start off from a stop, it will try and jump out of gear and then bump back into gear, but as soon as the road starts to level out, it won't slip anymore. It acts like it's losing fluid prime, but I don't know why.

I can go out on the road right now and stomp it to the floor a million times from a dead stop and it will shift perfect and never slip everytime, even with a load on the back, but when you get on a big hill and start from a dead stop (it won't do it if you're already moving) it will begin trying to jump out and back into gear. The transmission still shifts perfect and acts normal, but only when you start off on a big steep hill is when it does it, otherwise it's always normal. Any ideas? Thanks!

 

Mine is doing it too, but I think it's an engine misfire and not the tranny. I had a coil go out before and it does the same thing. Took it to the shop because I was out of town and they changed the plug out, but the problem still existed but not as bad. When I got home I asked a Ford mechanic and he said it was the coil. I changed out the coil for that plug and it solved the problem. I was lucky that time because it was bad enough to give me a code. This time it's intermittent and I can't get a code to show up. I have 89000 miles on it now so I'm thinking about a complete tune up with all new coils, plugs and wires. It usually does it when I'm going up an incline at lower RPM's, or when I'm pulling my boat. I'm sure it does it when I'm just cruising at low RPM's but it's not aas noticable.

 

Before getting all transmission trouble on us check the voltage available to the vehicle.
Voltage problems will cause erratic transmission operation.

 

Well, I don't think it's a missfire because what happens is the RPMs shoot up like it's in neutral and then drop fast once it bumps back into gear. I don't know what's causing it though. It only happens on hills. It feels just like it loses transmission fluid prime. Cause in the transmission all the fluid rushes to the back of the pan when you start off on a steep hill. I don't know if the filter was put on wrong, or what. I'm hoping I don't have to put a brand new transmission in it.

 

Have you checked the fluid level in the trany?

 

If it was mine I'd drop the pan and have a look. It's too much of a coincidence that it started happening after the filter and fluid change. If the fluid level is where it's supposed to be my guess would be incorrect filter or installation. Pretty cheap to check it now before it's too late. Just my two cents.

 

Agreed! Drop the pan and look, or take it to a reputable shop and have them do it.

 

Yeah, the fluid level is dead on full. And the people that did it are shadetree mechanics. And I had forgotten about the filter you're talking about. I bet that's what happened. I'll drop the pan in a few days and look. Thanks!

 

I once purchased some transmission filters for my 4R100 from a salvage sale.
I used one before a trip.
The transmission started puking fluid during a hard run.
I had to go buy a new filter and change it in a parking lot.
Boy was I glad that I had put a drain plug in the pan when I changed the filter the first time.

 

Thanks for this discussion guys! I was having the exact same symptoms when starting up a hill at low rpm. I disabled the O/D and it stopped, then went to Advance Auto and had them test the battery. It was down to about 50% of the 650 original cranking amps. This was the original battery and had lasted me over 6 years. Replaced it with an 850 and trans runs like a champ. I'm not an experienced mechanic, but the guy at advanced said that it's common for the O/D to jump out with low batter complicity.

Thanks again everyone!

 

^X2 Have the battery tested before you pull the trany control valve to repair it. If it is the original OEM battery it is good to remove.

 

Okay, maybe I jumped the gun. After changing the battery, I was not able to duplicate the bumping in the trans (that night). But it has come back, but seems to have changed. No it seem to do it only after gently applying accelerator on slight inclines. Before it would do it almost every time on a hill.

 

I have this exact problem! If anyone has any ideas please post them up.

 

Thinking it could be the trans vacuum modulator valve. Looks like I'm gonna have to have someone run a diagnostics and check. Man, they're proud of that thing aren't they. My truck only has 94k miles and I rarely pull anything but a small trailer. I've put all 94k and it's mostly commute and highway mile. Although the commute is over several mountains (AL mountains, not CO mountains).

I will add that before the last trans service, I remember the shifting being hard and it went away. I'm due for a service now. I'll try that and then diagnostics.

 

u may have a damaged control valve? The checkballs do get damaged. Possibly a problem with the filter in the pan/